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HomeMy WebLinkAboutCT 83-15; CAMINO POINTE; REGRADING AND TESTING OF COMPACTED FILL; 1984-10-30o 3467 Kurtz Street San Diego, California 92110 (619)224-2911 Woodward- Consultants October 30, 1984 Project No. 59331A-FC01 G & G Enterprises Incorporated 2204 Garnet Avenue San Diego, California 92109 Attention: Mr. Mark H. Cohen FINAL REPORT OF ENGINEERING OBSERVATION OF REGRADING AND TESTING OF COMPACTED FILL PADS 7 THROUGH 10 AND SLOPE REPAIR CAMINOPOINTE (CARLSBAD TRACT 79-27), CARLSBAD, CALIFORNIA Gent-men: - In accordance with your request, we have provided engineering services in conjunction with th regrading of the subject site. SCOPE OF WORK' \ Our services included: Providing periodic engineering observation of the grading operation Performing field density tests in the placed and compacted fill O Performing laboratory tests on representative samples of the material used for fill Providing professional opinions regarding the contractor's general adherence to plans and specifications SUMMARY OF GENERAL EARTHWORK AND TESTING Current site preparation, compaction, and testing were done between September 19 and October 24, 1984. In our opinion, based on our observation and testing, the work performed during that period was in general conformance with the Guide Specifications for Controlled Fill attached to our report entitled "Update Site. Reconnaissance and Update Soil Report, Camino Pointe (Carlsbad Tract 79-27), Carlsbad, California," dated June 8, 1984 and with a letter prepared by Forsum/Summers & Partners, Inc. entitled "Procedures for Repairing and Replanting Slopes Steeper than 2:1," dated August 14, 1984. . . Consulting Engineers. Geologists and Environmental Scientists Offices in Other Principal Cities - G & G Enterprises I•rpora ted Wclwàrd.Clyde Consultants Project No. 59331A-FC01 October 30, 1984 Page 2 Previous grading of the subject site was completed in September 1981 and is summarized in our report dated June 8, 1984. During the current grading period, fill was placed, compacted and tested on Pads 8 and 10. The depth of fill ranged from 2 to 6 feet. Pads 7 and 9 are cut pads; Pad 7 has natural ground at grade while Pad 9 is still underlain by compacted fill as a result of previous grading. Compacted fill was also placed in various slope areas on the project. Prior to placing fill, the areas to receive fill were scarified, watered and compacted On the slopes, the areas of sloughing were excavated to firm compacted material or natural ground and then replaced with properly moisturized compacted fill. During the regrading operation, compaction procedures were observed, and field density tests were made to help evaluate the relative compaction of the placed fill. Field observation and the results of field density tests indicate that the fill has been generally compacted to 90 percent or more of maximum dry laboratory density as determined in accordance with ASTM Test Method No. D1557-78. For reference, the approximate location of field density tests and the limits of compacted fill have.been.. 9corded on a copy of the grading plan. The results of 'field density tests, expressed as a percent of maximum laboratory dry density (relative compaction), are given on the attached forms. Laboratory tests were 'made on representative samples of the materials used for fill. The tests were performed to evaluate moisture-density relationships, maximum dry density, optimum moisture content, grain size distribution, and plasticity. The results •of laboratory tests are attached. , SUMMARY OF FINISH GRADE SOIL.' CONDITIONS Observation and laboratory tests indicate that, nonexpansive fill was placed within 2 feet of rough grade on Pads 8 and 10. An examination of Pads 7 and 9 did not reveal the presence of -expansive soil at rough pad grade. RECOMMENDATIONS Foundations for Structures on Nonexpansive Soil We recommend that foundations for single-story structures placed on nonexpansive, undisturbed soil or on nonexpansive, properly compacted fill be designed for a bearing pressure not exceeding 2000 psf (dead plus live load). We recommend that footings be founded at 'least 12 inches below finished grade, and have a minimum width of 12 inches. In our opinion, this bearing pressure can be increased by no more than one-third for loads that include wind or seismic forces. We recommend that footings for two-story structures in similar soils be 18 inches in depth. ' G & G Enterprises Incorporated Project No. 59331A-FC01 October 30, 1984 Page 3 Wdward.Clyde Consultants Slopes Fill slopes at the site have inclinations of approximately 1:1 (horizontal to vertical), and are approximately 8 to 10 feet high. Fill slopes were treated by compacting areas of repair with mechanical tampers. Fill slopes steeper than 2 to 1 are susceptible to shallow slope sloughing in periods of rainfall or if subjected to over irrigation; periodic rebuilding of the slopes may be required. We recommend that structures that will not tolerate differential settlements (such as foundations, swimming pools, concrete decks, walls, etc.) not be located within 8 feet of the top of a slope. We recommend that footings that are located within 8 feet of the top of a slope be extended in depth until the outer bottom edge of the footing is 8 feet horizontally from the outside face of the slope. Additional Fill and Utility Trenches This report discusses the fill placement observed by 'personnel from. our firm during the periods' specified. .We recommend, that any additional . fill placed, as well as backfill placed in utility trenches located within 5 feet of a building and 'deeper than 12 inches, or backfill placed in any trench located 5 feet or more from, a building and deeper than 5 feet, be compacted under our observation and tested to verify compliance with the earthwork specifications for the project. We should be contacted at least 24 hours prior to backfilhing operations. Drainage We recommend that positive measures be taken to properly finish grade each pad after structures and other improvements are in place, so that drainage waters from the pad and adjacent properties are directed off the pad and' away from foundations, floor slabs, and slope tops. Even when these measures are taken, a shallow ground-water or surface-water condition can and may develop in areas' where no such water condition existed prior to site development; this is particularly true where a substantial increase in surface-water infiltration results from landscape irrigation. LIMITATIONS The elevations of compaction tests shown as finished grade (FG) tests on the attached forms correspond to the elevations shown on the grading plans for Camino Pointe dated July 3, 1984, prepared by Pinney Engineering Associates, Inc. Elevations and locations used in this report were based on field surveys done by others. ' The soil conditions described in this report are based on observations and periodic testing. This office should be notified of any indications that soil G & G Enterprises Incorporated Adward-Clycle Consultants Project No. 59331A-FC01 October 30, 1984 Page 4 conditions are not as described herein. We will examine foundation excavations for each lot if we are requested to do so. For this report, rough 'lot grade is defined as that grade set in the field by the grade checker from reference stakes established by the surveyor, and represents rough grade at the time we were observing the grading operation. The . conclusions and opinions drawn from the test results and site observations apply only to our work with respect to regrading, and represent conditions at the date of our final site visit.. We will accept no responsibility for any subsequent changes made to this site by others, or by uncontrolled action of water, or. by failure of others to properly repair damages by uncontrolled action of water. Professional judgment represented in this report are based partly on our evaluations of the technical information gathered, partly on our understanding of the proposed construction, and partly on our general experience in the geotechnical field. Our engineering work and judgments rendered 'meet or exceed the standard of care of our profession at this time. We do not guarantee the performance of the project in any respect. If you have any questions, please give us a call. Very truly yours, WOODWARD-CLYDE CONSULTANTS Richard P. While R.E. 21992 . RPW / D T / ks Attachments (4) G & G Enterprises Inc. (1) City of Carlsbad Engineer OMPACTION TEST RESULT• Joa NAME CAMINO POINTE DATE REPORTED 10/30/84 JOB NUMBER 59331A-FC01 (BUILDING PADS) DATES COVERED SEPTEMBER 28, 1984 THROUGH OCTOBER 24, 1984 PAGE 1 OF 1 DATE TEST NUMBER RETEST OP LOCATION ELEVATION MOISTURE CONTENT FIELD DENSITY LABORATORY DENSITY RELATIVE COMPACTION OF TEST % DRY WY. PC? PC? % or LAB. DENS. SEPT 28 1 PAD #1 FG 137.5' 9.3 119.2 1260 94 1984 2 PAD #2 FG 136.0' 10.5 122.8 126.0 97 OCT 5 3 PAD #8 146' 8.7 120.2 126.0 95 4 I' 148' 9.9 121.7 126.0 96 OCT 8 5 PAD #6 134' 10.5 118.0 126.0 93 6 " " 136' 11.7 123.l 126.0 97 7 11 139' 10.5 125.2 126.0 99 OCT 10 8 MINOR RECREATION PAD 150' 12.3 127.1 128.0 99 9 PAD #10, N.E. CORNER 157' 11.1 127.3 128.0 99 OCT -11 10 PAD #10, N.E. COR. FG 159.5' 10.5 123.7 126.0 98 OCT 12 11 MINOR REC. AREA FG 152.0' 11.1 119.7 126.0 95 OCT 24 12 PAD #10 FG 159.0' 8.7 120.1 126.0 95 - 13 PAD #8 FG 152.0' 7.5 122.3 126.0 97 OMPACTION TEST RESULTO Joi NAME CAMINO POINTE DATE REPORTED 10/30/84 JOB NUMBER 59331A-FC01 (SLOPE REPAIR) DATES COVERED SEPTEMBER 19, 1984 THROUGH OCTOBER 4, 1984 PAGE or DATE TEST RETEST NUMBER OF SEPT 19 1 1984 2 3 4 SEPT 22 5 6 SEPT 24 7 SEPT 26 8 SEPT 27 9 10 SEPT 28 11 12 OCT3 13 OCT4 14 MOISTURE YIELD LABORATORY RELATIVE ELEVATION CONTENT DENSITY DENSITY COMPACTION OF TEST % DRY WT. PCF PCP % or LAB. DENS. +3' 9.8 122.2 131.0 93 +5' 8.7 119.9 128.0 93 +8' 9.3 116.3 128.0 90 +11' 11.1 126.3 128.0 96 +3' 9.0 125.7 131.0 95 +61 8.7 124.2 131.0 94 +8' 10.5 124.7 131.0 95 +3' 13.5 125.4 128.0 98 +6' 9.3 118.2 128.0 92 +8' 10.5 122.4 128.0 95 ±3' 10.5 129.8 131.0 99 +6' 9.9 127.8 131.0 97 +3' 11.1 127.5 128.0 99 +6' 9.9 121.4 126.0 . 96 LOCATION AREA #6 II II I, II 'I AREA #4 II II AREA #4 AREA #5 AREA #5 AREA #3 I, II AREA #1 AREA #1 Woodward-Clyde Consultants - CONSULTING ENGINEERS. GEOLOGISTS AND ENVIRONMENTAL SCIENTISTS 1001- PLASTICITY CHARACTERISTICS 1 2 3 Liquid Limit, % 21 27 31 Plasticity Index, % 6 13 20 Classification by Unified Soil SC SC SC Classification System [oIiI.J.]R*lflUflUI ___ •ULI __I 150 140 ZERO AIR VOIDS CURVES —2.80 SG - 2.70 SG - 2.60 SG 2.50 SG 60 I— z w 40 0 cc a- 20 0 1 1 Iii 11 If liii III I I 1000 100 10 1.0 0.1 J 0.01 0.001 GRAIN SIZE. mm MECHANICAL ANALYSIS 130 120 DIRECT SHEAR TEST DATA 1 2 3 DryDensity,pcf - - - initial Water Content, % - - - FinalWaterContent,% - - - ApparentCohesion,psf - - - ApparentFrictionAngle,degrees - - - SWELL TEST DATA . 1 2 3 InitialDryDensity,pcf - - - InitialWaterContent,% - - - FinalDryDensity,pcf - - - FinalWaterContent,% - - - Load,psf - - - Swell,percent - - - 9O Maximum Dry Oi 0 2 0 3 Density, pcf 131.0 128.0 126.0 Optimum Moisture Content,% 1 9.01 9.5 8.5 80 I I MOISTURE CONTENT,% o 10 20 30 LABORATORY COMPACTION TEST SAMPLE LOCATION 1 STOCKPILE 3 FILL AREA MECHANICAL/MOIST. 40 LABORATORY COMPACTION TEST METHOD: ASTMD 155778A - . FILL SUITABILITY TESTS CAMINO POINTE DRAWN BY: ch CHECKED BY: 444/I PROJECT NO: 59331A—FC01 DATE: 10/30/84 J FIGURE NO: 1 W000WARDCLYDE CONSULTANTS